• Journal of Power System Engineering
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• v.9 no.3
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• pp.33-38
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• 2005

The aerodynamic performance of a cross-flow fan is strongly influenced by the various design factors of a rear-guider and a stabilizer. The purpose of this paper is to investigate the effects of a rear-guider and a stabilizer on the aerodynamic performance of a cross-flow fan. The design factors considered in this paper are a rear-guider clearance, a stabilizer clearance, and a stabilizer setup angle, respectively. This experiment was carried out with a constant revolution number of 700 rpm in a cross-flow fan installed in the fan tester. The static pressure, flowrate, torque, and revolution number were measured in this paper. Also, the pressure coefficient and the efficiency were analysed according to the various assembly conditions using a stabilizer setup angle, a stabilizer clearance, and a rear-guider clearance in the indoor room air-conditioner.

• The KSFM Journal of Fluid Machinery
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• v.5 no.3 s.16
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• pp.72-77
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• 2002

• The KSFM Journal of Fluid Machinery
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• v.4 no.2 s.11
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• pp.53-58
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• 2001

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.1
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• pp.75-84
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• 2000

Performance and flow characteristics of a small forward swept propeller fan for home refrigerators are studied experimentally. An unusual discontinuity is observed in the performance curve of the fan. Mean flow fields measured with as-hole Pitot probe reveal that the flow is axial at the high flow rate and radial at the low flow rate. The flow structure changes abruptly across the discontinuity. Unsteady flow measurements with a set of hot-wire probes indicate that near the discontinuity a single-cell stall rotates at 40% speed of the fan speed, while away from the discontinuity the flow shows periodic variation corresponding to the blade passage frequency. Phase-lock averaged flow fields measured with a triple-sensor hot-wire probe show that there appears radially inward flow over the pressure side of the blade and the outward passage flow over the tip.

• The KSFM Journal of Fluid Machinery
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• v.1 no.1 s.1
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• pp.32-40
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• 1998

Aerodynamic performance of a cooling fan of driving motor was enhanced modifying the vane-shroud configuration. Performance of a target model was evaluated to obtain baseline data. The aerodynamic performance and sound pressure level were tested and measured with different numbers of vane of increased length. The tested models show high and stable performance and low values of specific noise level. The long vane-shroud structure induces more stable through flow and decreases the tip leakage flow, which contributes to the increases of performance and efficiency. The sound pressure level increases for the modified model, however, specific noise level decreases.

• Journal of KSNVE
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• v.10 no.3
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• pp.430-436
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• 2000

The cross-flow fans have been widely used to constitute the air moving systems in many air-ventilating and air-conditioning units. The cross-flow fan system has many design parameters which have crucial influence on the performance and the noise characteristics of the units. As a result there are many difficulties in the design stage of the system and the general design guide has not been sufficiently established yet. This study presents the experimental results of the parametric investigation of some chosen design parameters which are directly related to the shape of the stabilizer the profile of the scroll casing and the diffusion angle of the flow exit. The results are expressed in terms of the fan performance and the specific sound pressure level characteristics. Some parameters have been found to have crucial effects on the system performance/noise characteristics and should be considered with care in the design stage.

• Journal of Power System Engineering
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• v.13 no.4
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• pp.31-37
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• 2009

The purpose of this numerical study was to investigate performance characteristics for cooling tower axial fans with sweep. Performance data for the fans with various sweep angles were obtained in terms of the setting angle at a constant flow rate. Viscous flow calculations were carried out to obtain Performance data of the total pressure rise and hydraulic efficiency. A solution of the Ffowcs Williams-Hawkings equations was used to calculate the sound pressure level at three times fan diameter away from the fan. The calculated performance data well represented performance characteristics of the cooling tower axial fan. The total pressure rise and hydraulic efficiency at the same setting angle decreased with sweep angle. Sound pressure level slightly decreased for the fan with a sweep angle of 10 degree. No significant effect of the sweep geometry was found on the sound pressure level.

• The KSFM Journal of Fluid Machinery
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• v.8 no.5 s.32
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• pp.29-34
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• 2005

In this study, the effect of flow settling means on the performance of fan tester were numerically investigated by using a computational fluid dynamics (CFD). The airflow rate was calculated from the pressure differential across a flow nozzle in the measuring plane and the flow settling means were generally installed in the chamber of the fan tester to provide proper airflow patterns ahead of the measuring plane. The predicted nozzle differential pressures with uniform inlet velocities were compared with the values of the ANSI/AMCA 210-99 to verify the performance of the commercial CFD code CFX 5.6. The influence of flow settling means on the measurement of airflow rate in a fan tester were discussed with various porosities and inlet jet velocities. The results obtained show that the proper band of porosities exist to meet the AMCA standard in a specified inlet jet velocity.

• 유체기계공업학회:학술대회논문집
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• 2001.11a
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• pp.43-47
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• 2001

A program to design an axial flow fan, analyze the performance and predict the noise was developed. In order to develop the low noise fan, that program is compulsory. This software is composed of three parts : the geometric design module, the performance analysis module, the fan noise prediction module. In order to analyze the performance, three dimensional vortex panel method is used. The unsteady flow field was analyzed by time-marching free wake method. The unsteady force data is then used in predicting the noise. Farassat's equation is used to predict the noise of fan.

• Journal of computational fluids engineering
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• v.15 no.4
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• pp.109-114
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• 2010

In a fan design, CFD analysis, which is very useful for mechanical design relating to the heat and fluid dynamics, is one of the most popular tools. However, since the CFD analysis is conventionally carried out with the constant fan speed condition, the speed change, induced by the air flow rate and motor characteristics, is hardly modeled. And, consequently, the remarkable difference exist between analysis and experimental results. In this paper, we has proposed a method of setting the varying fan speed as a boundary condition considering air flow rate and motor torque-speed characteristics. The effectiveness of the proposed method is verified by comparison with experimental results.